public void ExecuteScalarByExpression()
{
Expression<Func<Customer, bool>> expression = x => x.ID == 1;
Expression<Func<Customer, int>> column = c => c.ID;
var provider = new IProvider();
var command = new ICommand();
provider.CommandBuilder.Setup(c => c.CreateExecuteScalarCommand<Customer>(column, expression)).Returns(command.Object);
provider.CommandExecutor.Setup(c => c.ExecuteScalar(command.Object)).Returns(2);
var target = new DataSession(provider.Object);
var result = target.ExecuteScalar(column, expression);
provider.CommandExecutor.Verify(c => c.FinalizeCommand(command.Object));
Assert.AreEqual(result, 2);
}
public void ExecuteScalarByExpressionThrowsUnableToCreateCommandException()
{
try
{
Expression<Func<Customer, bool>> expression = x => x.ID == 1;
Expression<Func<Customer, object>> column = c => c.ID;
var provider = new IProvider();
provider.CommandBuilder.Setup(c => c.CreateExecuteScalarCommand<Customer>(column, expression)).Returns(
default(Data.ICommand));
var target = new DataSession(provider.Object);
target.ExecuteScalar(column, expression);
}
catch (Exception ex)
{
Assert.IsTrue(ex is UnableToCreateCommandException);
}
}
public void ExecuteScalarByExpressionThrowsInvalidCastException()
{
Expression<Func<Customer, bool>> expression = x => x.ID == 1;
Expression<Func<Customer, int>> column = c => c.ID;
var provider = new IProvider();
var command = new ICommand();
provider.CommandBuilder.Setup(c => c.CreateExecuteScalarCommand<Customer>(column, expression)).Returns(command.Object);
provider.CommandExecutor.Setup(c => c.ExecuteScalar(command.Object)).Returns("HelloWorld");
try
{
var target = new DataSession(provider.Object);
var result = target.ExecuteScalar(column, expression);
provider.CommandExecutor.Verify(c => c.FinalizeCommand(command.Object));
}
catch (Exception ex)
{
Assert.IsTrue(ex is InvalidCastException);
}
}
public void ExecuteScalarByExpressionThrowsArgumentNullException()
{
var provider = new IProvider();
var target = new DataSession(provider.Object);
Expression<Func<Customer, bool>> expression = null;
Expression<Func<Customer, object>> column = null;
var result = false;
try
{
target.ExecuteScalar(x => x.ID, expression);
}
catch (Exception ex)
{
result = ex is ArgumentNullException;
}
try
{
target.ExecuteScalar(column, x => x.ID == 1);
}
catch (Exception ex)
{
result = ex is ArgumentNullException;
}
Assert.IsTrue(result);
}
